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Great Blue Heron fannini ssp.

Ardea

herodias

fannini

Great Blue Heron are a member of the family Ardeidae (Herons, Egrets and Bitterns), represented by ~64 species globally. Although herons resemble birds such as cranes, they are not in the same family. Two subspecies occur in BC, the coastal fannini ssp. and the interior herodias ssp.

Height: 60 cm, Wingspan 1.5 m. Both sexes are similar. Adult Great Blue Heron are tall, long-legged wading birds with a sinuous neck held in an “S” curve at rest and in flight. The long thick bill is yellow and black, the head and face are white. In mature birds, plumage is a steel blue-grey with dark blue-grey flight and tail feathers. As birds mature a distinctive black plume extends from above the eye to beyond the back of head and a bib of long trailing plumes on the chest and scapula area become more pronounced. Juveniles are grey-brown on the back and upper wing plumage and lack the black eyebrow and adult head and bib plumes.

Download Species Fact Sheet in PDF

Status

Global Status:

G5T4

Provincial Status:

S23B,S4N

SARA Status:

Special Concern

BC List Status:

Blue (Considered to be of Special Concern)

Similar Species

Great Blue Heron are often mistakenly referred to as a “cranes” due to the fact that the closest look alike in size is the Sandhill Crane (the only species of crane in BC). Unlike Great Blue Heron, Sandhill Crane have a large patch of bare, red skin above the eye, fly with a fully extended neck and nest on the ground. Cranes also have a distinct “bustle” or group of large curved feathers over the lower back and tail area.

Ecology

Range

Elevation: 0-1100 m. The fannini subspecies of Great Blue Heron is found throughout the Coast Region. While foraging and breeding sites are quite dispersed, this subspecies is more common on the South Coast especially in association with low elevation lakes, wetlands, sloughs and estuaries. The major nesting colonies (“heronries”) on the South Coast include: Tsawwassen, Bowen Island, Deer Lake, UBC (main campus) and West Vancouver. Many of these locations support >100 nesting pairs. Other heronries occur on the Southern Gulf Islands and southeast Vancouver Island. A major heronry located at the confluence of the Coquitlam and Fraser Rivers adjacent to Colony Farm Regional Park became abandoned around 2012. Although some nesting may still be occurring there. It is estimated that approximately
4-5000 breeding birds make up the coastal subspecies population in BC, with some heronries like Tsawwassen supporting at least 10% of that population.
South Coast BC Distribution. Main breeding colonies (green) and potential occurrence range (red-dotted line)

Habitat

Habitat (especially during breeding season) ranges from riparian areas, estuaries, lakes and lowland rivers and streams. Foraging habitat includes: Eel grass beds, mudflats, agricultural fields and old-field (mainly short-grass or mowed), wharves, beaches, irrigation ditches, urban lakes, streams, drainage ditches and backyard ponds. During non-breeding periods birds roost high up in mature trees in close proximity to foraging sites. Heronries are typically found within 10 km of foraging habitats. Though generally associated with stands of trees well away from noise, light and human disturbance, some heronries (e.g. Stanley Park), have become established in dense urban areas. Canopy closure is a factor for heronries, typically being >80%, though birds have been known to use stands with more open canopies. Heronries can be over 350 nests and sites are reused in successive years. Small nesting colonies are more common on the Sunshine Coast and on Vancouver Island. Nests are located at 4-70 m above ground and consist of large stick platforms, <1 m diameter. Nests are constructed on the horizontal branches of mature trees, often Black Cottonwood, Bigleaf Maple or
conifers. Nests are lined with twigs; bark strips, coniferous boughs and rushes. Both the nest and the ground beneath are often covered in droppings, discarded food, and occasionally dead chicks.

Diet

Primarily a fish eater (pisciverous), this subspecies also exploits a range of amphibians including invasive species such as Green Frog and American Bullfrog. Small mammals such as Townsend’s Vole, mice and shrews are stalked in meadows and agricultural fields and may form an important component of the diet in winter in certain areas.

Life Cycle

For colony specific details on Pacific Great Blue Heron breeding and rearing chronology contact the Great Blue Heron Working Group.

Threats

Habitat loss due to significant urbanization, draining and infilling of wetlands, foreshore development, logging and removal of riparian forest.

Low breeding success and high rates of nest abandonment in response to disturbance and human activities. Canopy removal or clearing near a nesting area can cause nest abandonment and chick mortality.

Increased predation by recovering bald eagle populations may result in low breeding success and abandonment of some nesting colonies.

Conservation and Management

Apply the BC Ministry of Environment’s most recent version of the “Develop with Care, Great Blue Herons Fact Sheet #11” which contains recent updates and adjusted timing windows and buffers for the subspecies. Foresters applying buffers and timing windows as found in Accounts and Measures for Managing Identified Wildlife Great Blue Heron Herodias ardea under the Forest and Range Practices Act should consider harmonizing activities and practices to reflect the most recent science reflected in the Develop With Care Guidelines. Assess, inventory and monitor using methodology set out by the Heron Working Group and described by Vennesland & Norman (2006), Survey Protocol for Measurement of Nesting Productivity of Great Blue Heron Nesting Colonies. Integrate complimentary methodologies as found in the Inventory Resource Information Standards Committee Inventory Methods for Colonial-Nesting Freshwater Birds #8 (Version 2.0).
The fannini subspecies of Great Blue Heron is listed under the Species at Risk Act (SARA), is subject to protections and prohibitions under the Federal Migratory Birds Convention Act and BC Wildlife Act and is Identified Wildlife under the Forest and Range Practices Act. Habitat for this species may also be governed under provincial and federal regulations including the Fish Protection Act and Federal Fisheries Act as well as Regional and local municipal bylaws.

RESOURCES

Summary of relevant background information on the Pacific Great Blue Heron and outline a standard survey protocol for the documentation of reproductive productivity at Pacific Great Blue Heron colonies in British Columbia and Washington State.

The Heron Working Group is a consortium of individuals from university, government and conservation organizations interested in the conservation of the ÎPacificâ Great Blue Heron (Ardea herodias fannini). We communicate mostly through e-mail and occasionally by meetings. Our aim is to ensure that the Pacific Great Blue Heron continues to thrive as species throughout its range. We collaborate on designing research and census protocols, conservation advice, seeking funding support, and providing this web site forum for information.

A source for authoritative conservation information on thousands of plants and animals and hundreds of ecological communities in BC. From here connect to all provincial and federal recovery plans (including the SARA Registry), COSEWIC (Committee on the Status of Endangered Wildlife in Canada), Identified Wildlife guidance and conservation requirements for specific species and ecological communities of conservation concern impacted by forestry activities) and links to E-Flora and E-Fauna (the Electronic Atlas of the Plants and Wildlife of British Columbia).

A joint venture resource providing comprehensive information on a range of species and ecological communities specific to the Coast Region of BC (including the South, Central and North Coast, Vancouver Island and Haida Gwaii).

Credits

Species Profile prepared by: Pamela Zevit, RPBio, South Coast Conservation Program, and K. Welstead, FLNRO in partnership with: International Forest Products (Interfor), Capacity Forestry (CapFor). Funding for this factsheet was through the Sustainable Forestry Initiative (SFI): http://www.sfiprogram.org/ Updated and revised by: Isabelle Houde, RPBio in consultation with the SCCP. Part of the National Conservation Plan, this project was undertaken with the financial support of the Government of Canada. Dans le cadre du Plan de Conservation National, ce projet a été réalisé avec l’appui financier du Gouvernement du Canada. Every effort has been made to ensure content accuracy. When managing for this species and for the most current information please also contact the Heron working Group or the regional species at risk biologist. Comments or corrections should be directed to the South Coast Conservation Program: info@sccp.ca. Content updated March 2015. Image Credits: Adult and immature Great Blue Heron: Winnu Flickr, Sandhill Crane: Tom Freidel Flickr, Habitat: Margaret Cuthbert. Only images sourced from “creative commons” sources (e.g. Wikipedia, Flickr, U.S. Government) can be used without permission and for non-commercial purposes only. All other images have been contributed for use by the SCCP and its partners/funders only.

SOUTH COAST CONSERVATION PROGRAM

French translation of SCCP original content available upon request.

Images sourced from “creative commons” sources (e.g. Wikipedia, Flickr, U.S. Government) can be used without permission and for non-commercial purposes only. All other images have been contributed for use by the SCCP and its partners/funders only. Content on this site may not display correctly with older browsers. Updating to the latest version of your browser is recommended.